Linux: Use After Free
CVE-2024-56652 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions b0193a31a0ca5a0f9e60bb4a86537d46b98111b8, d7b028656c29b22fcde1c6ee1df5b28fbba987b5 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to b0193a31a0ca5a0f9e60bb4a86537d46b98111b8 or d7b028656c29b22fcde1c6ee1df5b28fbba987b5, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.6 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | dd08ebf6c3525a7ea2186e636df064ea47281987 up to, but not including, b0193a31a0ca5a0f9e60bb4a86537d46b98111b8; dd08ebf6c3525a7ea2186e636df064ea47281987 up to, but not including, d7b028656c29b22fcde1c6ee1df5b28fbba987b5; 6.8 | b0193a31a0ca5a0f9e60bb4a86537d46b98111b8, d7b028656c29b22fcde1c6ee1df5b28fbba987b5 |
| Linux | Linux Kernel | 6.8 up to, but not including, 6.12.6; 6.13 | 6.12.6 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: drm/xe/reg_sr: Remove register pool That pool implementation doesn't really work: if the krealloc happens to move the memory and return another address, the entries in the xarray become invalid, leading to use-after-free later: BUG: KASAN: slab-use-after-free in xe_reg_sr_apply_mmio+0x570/0x760 [xe] Read of size 4 at addr ffff8881244b2590 by task modprobe/2753 Allocated by task 2753: kasan_save_stack+0x39/0x70 kasan_save_track+0x14/0x40 kasan_save_alloc_info+0x37/0x60 __kasan_kmalloc+0xc3/0xd0 __kmalloc_node_track_caller_noprof+0x200/0x6d0 krealloc_noprof+0x229/0x380 Simplify the code to fix the bug. A better pooling strategy may be added back later if needed. (cherry picked from commit e5283bd4dfecbd3335f43b62a68e24dae23f59e4)
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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